Potential cross infection in the dental operatory may jeopardize clinicians, ancillary personnel, and patients, as well as their families. Recent attention to infection control by dentists, a byproduct of the AIDS phenomenon in America, has revealed that there is great variation in practice, and lack of knowledge about proper infection control. A mail questionnaire will be designed, pretested, and used to collect national data from a sample of general dental practitioners. The sampling design will facilitate national estimates and also the detection of significant differences between high risk urban, other urban, and rural practitioners within age categories. Data will be collected on such infection control behaviors as use of barrier techniques and methods for disinfection or sterilization of instruments. Data will also be collected on a variety of independent variables, including dentists' knowledge of the theory underlying infection control practices and additional variables suggested by the literature of diffusion of innovation/utilization of scientific knowledge. Specific aims include 1) the creation of an infection control behavior scale; 2) assessment of level of infection control behavior among the sample's strata; 3) assessment of level of knowledge of the theoretical principles underlying infection control behaviors among the sample's strata; (4) testing the extent to which knowledge predicts behavior in general and in the subsamples; (5) identification of the most salient correlates and predictors of infection control behaviors; and (6) comparative assessment of differences, if and, which exist among strata with regard to characteristics, correlates, and predictors of infection control behavior. Methods to be used will include the examination and testing of variable distributions through the use of t-tests, one-way analysis of variance, and chi-squares; factor analytic data reduction strategies followed by unit-weighted index construction; dependent variable scale construction re infection control behavior; and correlational and multiple regression analyses examining relations between dependent-independent variables. Longer term goals include using what is learned about dentists' infection control behavior and their predictors in order to design and target groups for future interventions associated with a) reducing the risk of cross-infection; b) reducing the anxiety of dentists so that fewer patients are likely to be denied service unnecessarily; c) making dentists more aware of oral diagnostic markers of important infectious disease: d) building theory about predicting-behavior.